Caracterização dos efeitos da exposição ao etanol na resposta inflamatória gerada por aspergillus fumigatus

Abstract

Alcohol consumption causes numerous harm to the health of consumers due to the toxicity of its metabolism by-products, and is considered a risk factor for the development of opportunistic lung infections. The aim of the present study was to characterize the persistent effects of chronic consumption and acute exposure to ethanol on the inflammatory response during A. fumigatus infection. To assess the persistent effects of chronic consumption, C57/BL6Unib mice were treated with an alcoholic solution (20% v/v) for 12 weeks, and their bone marrow (BM) was transplanted into untreated control mice after irradiation. After 30 days of recovery, these animals were infected intranasally with 1x108 conidia of A. fumigatus and after 48 hours they were euthanized. The results show that the animals that received MO from treated animals (EtOH-chimera) showed an increased lung injury, hemorrhage and cell death. In the lungs, we observed an increased production of CXCL2, IL-6 and TNF-ɑ in the EtOH-chimera animals, besides a decrease in the of neutrophils to the alveoli after infection, even though they exhibited similar amounts of neutrophils in the blood and lungs. Phagocytosis and fungal clearance of ex vivo neutrophils were also decreased in EtOH-chimera animals. Despite the suppressive effect expressed on neutrophils, bone marrow-derived macrophages from the EtOH chimera have greater depurative capacity and greater production of TNF and CXCL2. These changes persist after bone marrow transplantation and several hematopoietic cycles, directly affecting the production of mature cells and an appropriate inflammatory response, which leads us to hypothesize epigenetic mechanisms that maintain these changes in precursor cells. To assess the effect of acute ethanol exposure, we exposed RAW 264.7 to ethanol for 48 hours. We observed that concentrations of 100 and 250 mM are toxic to cells, therefore, we use non-cytotoxic concentrations of ethanol below. After 4 hours of stimulation, our data demonstrate that macrophages exposed to ethanol have a reduced capacity for phagocytosis of conidia, fungal clearance and production of TNF-ɑ, which may be related to metabolic reprogramming and increased glycolysis, demonstrated by the significant increase in lactate by ethanol treated cells. We can conclude that, regardless of the amount and frequency of ethanol exposures, the immune system's ability to deal with the infection caused by A. fumigatus is diminished, which may explain why people with a history of ethanol consumption have a susceptibility to aspergillosis, and may represent new target mechanisms for the development of therapeutic treatments for the alcoholic population.